New method for the synthesis of unsymmetrical tertiary amines

ABSTRACT

Disclosed is a new method for the synthesis of unsymmetrical tertiary amines using alcohol and an imine, and to new tertiary amines.

The present invention relates to a new method for the synthesis of unsymmetrical tertiary amines using an alcohol and an imine, as well as novel tertiary amines.

The development of simple reactions for C—N bond formation is an important challenge to chemists. Substituted amines have widespread applications in the synthesis of drugs, dyes, detergents, perfumes, pharmaceuticals, emulsifiers, crop protection agents, etc.

Among the various strategies for the synthesis of amines, the development of direct amination reactions of alcohols for the rapid generation of secondary or tertiary amines, from simple and readily available starting materials, is at the forefront of fine chemical synthesis and involves a high potential for industrial development.

Among these methods, the direct amination of alcohols by borrowing of hydrogen (or hydrogen transfer) has been recognized as one of the most practical for the industrial production of trisubstituted alkylamines. This atom efficient reaction and the wide availability of the alcohols, combined with the fact that water is the only byproduct of these reactions, responding to general principles of green chemistry, are the reasons for its widespread use.

This amination has been performed for the first time with late transition metals of the second and third periods, which were rapidly followed by much more elaborate complexes (Ru, Rh, Ir, Os). The current trend is to replace these noble elements with less expensive and more abundant transition metals of the first period. In this respect, significant improvements have recently been made using manganese, iron or cobalt catalysts. However, there is still a significant need for more active catalysts working in milder conditions, which allow greater functional tolerance of the substrate and improve the selectivity and TON (Turn-Over Number).

If we wish to access the synthesis of tertiary amines by this strategy, we can only have access to trisubstituted amines with 1 or 2 different groups. However, there are no direct amination methods to access tertiary amines having 3 different substituents. The direct conversion of primary amines, via the synthesis of imines, to tertiary amines bearing three different substituents is thus unknown to date.

One of the aims of the invention is the provision of a new method for the synthesis of tertiary trisubstituted asymmetric amines, simple to implement, fast and applicable to a wide variety of substrates.

One of the other aims of the invention is the possibility of using a catalyst derived from an abundant and inexpensive metal allowing to work under mild conditions.

One of the other aims of the invention is the ability to access the synthesis of a wide variety of tertiary amines, in a simple manner.

This new method has the advantages of being simple to implement, fast, applicable to a wide variety of substrates, using a catalyst derived from an abundant and inexpensive metal and allowing to work under mild conditions.

The present invention relates to the use of an alcohol, in particular primary or secondary, with the exception of methanol, and of an imine in the implementation of a method of preparation of tertiary amines.

Within the meaning of the invention, the expression “primary alcohol” refers to a compound of formula R—O—H wherein the carbon atom carrying the hydroxyl group also carries two hydrogen atoms.

Within the meaning of the invention, the expression “secondary alcohol” refers to a compound of formula R—O—H wherein the carbon atom carrying the hydroxyl group carries a single hydrogen atom.

Within the meaning of the invention, the expression “tertiary amine” refers to a compound of formula N—R₃ in which R is not a hydrogen atom.

The present invention also relates to the use of an alcohol, in particular primary or secondary, with the exception of methanol, and of an imine in the implementation of a method of preparation of tertiary amines, in particular carrying three different substituents.

According to another embodiment, the invention relates to the use of an alcohol, in particular primary or secondary, with the exception of methanol, and of an imine in the implementation of a method of preparation of tertiary amines, wherein the prepared tertiary amine carries three all different substituents with respect to each other and different from a hydrogen atom.

According to another embodiment, the invention relates to the use of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl and of an imine of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the implementation of a method of preparation of tertiary amines of formula (E)

wherein R₁, R₂, R₃, R₄ are as defined above.

Within the meaning of the invention, the expression “C₁ to C₁₀” refers to an acyclic saturated carbon chain, linear or branched, comprising 1 to 10 carbon atoms. Examples of C₁ to C₁₀ alkyls include methyl, ethyl, propyl, butyl, pentyl, hexyl or heptyl.

Within the meaning of the invention, the expression “C₂ to C₁₀” refers to an acyclic saturated carbon chain, linear or branched, comprising 2 to 10 carbon atoms. Examples of C₂ to C₁₀ alkyls include ethyl, propyl, butyl, pentyl, hexyl or heptyl. The definition of propyl, butyl, pentyl, hexyl or heptyl includes all possible isomers. For example, the term butyl comprises n-butyl, iso-butyl, sec-butyl and tert-butyl. The alkyl may be substituted at different positions with one or more functional groups such as halogen, alkoxyl, amino, nitro, cyano, trifluoromethyl or carboxylic ester.

Within the meaning of the present invention, the expression “C₃ to C₁₀ cycloalkyl” denotes a mono-, bi- or tri-cycle, saturated or partially saturated, comprising from 3 to 10 carbon atoms.

Within the meaning of the invention, the expression “C₁ to C₁₀ carbonyl derivative” denotes a compound comprising 1 to 10 carbon atoms and having a double bond between a carbon atom and an oxygen atom.

Within the meaning of the invention, the expression “C₃ to C₁₀ formate” means a compound of formula HCOOR comprising 3 to 10 carbon atoms.

According to the above embodiment, the invention relates to the use of an alcohol of formula (C), that can be a primary or secondary alcohol, and of an imine of formula (D), that can be an aldimine or a ketimine.

Within the meaning of the invention, the expression “aldimine” denotes an imine of formula (D)

wherein R₂ represents a hydrogen.

Within the meaning of the invention, the expression “ketimine” denotes an imine of formula (D)

wherein R₂ is not a hydrogen atom.

According to a particular embodiment, the invention relates to the use of a primary alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl and of an imine of formula (D)

wherein R₁ represents an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₂ represents a hydrogen, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the implementation of a method of preparation of tertiary amines of formula (E)

wherein R₁, R₂, R₃, R₄ are as defined above.

According to another particular embodiment, the invention relates to the use of a primary alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, and of an imine of formula (D)

wherein R₁ and R₂ represent an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the implementation of a method of preparation of tertiary amines of formula (E)

wherein R₁, R₂, R₃, R₄ are as defined above.

According to another particular embodiment, the invention relates to the use of a secondary alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, and of an imine of formula (D)

wherein R₁ represents an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₂ represents a hydrogen, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative of, or a C₃ to C₁₀ formate, in the implementation of a method of preparation of tertiary amines of formula (E)

wherein R₁, R₂, R₃, R₄ are as defined above.

According to another particular embodiment, the invention relates to the use of a secondary alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, and of an imine of formula (D)

wherein R₁ and R₂ represent an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the implementation of a method of preparation of tertiary amines of formula (E)

wherein R₁, R₂, R₃, R₄ are as defined above.

According to another embodiment, the invention relates to the use of an alcohol, in particular primary or secondary, and of an imine in the implementation of a method of preparation of tertiary amines wherein the preparation of tertiary amines is performed in the presence of a catalyst comprising an iron(0) complex.

Within the meaning of the invention, the expression “catalyst” refers to a compound that allows, increases the speed of a chemical reaction.

Within the meaning of the invention, the expression “iron(0) complex” denotes a chemical structure in which an iron atom in the oxidation state 0 is linked to multiple ligands.

Indeed, the inventors were able to go beyond the conventional reactivity of alcohols using iron(0) catalysts which are able to catalyze the addition of primary alcohols and secondary on imines by N-alkylation. This method has no literature precedent and allows for the synthesis of amines trisubstituted with three different groups, that are inaccessible by conventional methods.

According to another embodiment, the invention relates to the use of an alcohol, in particular primary or secondary, and of an imine in the implementation of a method of preparation of tertiary amines, wherein the preparation of tertiary amines is performed in the presence of a catalyst comprising an iron(0) complex chosen from the following formulas:

in which Ts=tosyl

TMS=trimethylsilyl

TBDMS=tert-butyldimethylsilyl

TIPS=triisopropylsilyl

and preferably being of the following formula (B):

in which TBDMS=tert-butyldimethylsilyl

Ts=tosyl

The catalyst used is either the catalyst of formula (B) prepared prior to the preparation of the tertiary amines, or the catalyst formed in situ during this preparation via the addition of trimethylamine oxide to the complex of formula (A):

This cyclopentadienone tricarbonyl-type catalyst of formula (A) must first be activated by the addition of an additive, trimethylamine oxide, to remove a CO type ligand, which makes it active but this step requires the use of a glove box. The inventors have demonstrated that the preformed catalyst of formula (B), through stabilization of an acetonitrile ligand, could be manipulated in ambient air, and was equally active in catalysis.

According to another embodiment, the invention relates to the use of an alcohol, in particular primary or secondary, and of an imine, in the implementation of a method of preparation of tertiary amines wherein the preparation of tertiary amines is performed in the presence of a catalyst comprising an iron(0) complex chosen from the following formulas:

in which Ts=tosyl

TMS=trimethylsilyl

TBDMS=tert-butyldimethylsilyl

TIPS=triisopropylsilyl

and preferably being of the following formula (B):

in which TBDMS=tert-butyldimethylsilyl

Ts=tosyl

Other examples of catalysts that can be used are the following:

According to another embodiment, the invention relates to the use of an alcohol, in particular primary or secondary, and of an imine in the implementation of a method of preparation of tertiary amines wherein the preparation of amino tertiary is performed in the presence of a catalyst comprising an iron(0) complex, wherein the catalyst used is either the complex of formula (B) formed prior to the preparation of tertiary amines, or the catalyst formed in situ during said preparation of tertiary amines by adding trimethylamine oxide to the complex of formula (A):

According to a particular embodiment, the invention relates to the use of an alcohol, in particular primary or secondary, and of an imine in the implementation of a tertiary amine preparation method, wherein the alcohol of formula (C) is chosen from ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, amyl alcohol, isopentanol, neopentyl alcohol, methyl-n-propylcarbinol, hexan-1-ol, heptan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol, ethylene glycol.

According to another particular embodiment, the aforementioned imine is chosen from

The present invention also concerns a method of preparation of tertiary amines of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said tertiary amine of formula (E) carrying in particular three different substituents, different from a hydrogen atom; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.

According to the above embodiment, the invention relates to a method of preparation of tertiary amines of formula (E) comprising a step of alkylation of an alcohol of formula (C) that can be a primary or secondary alcohol on an imine of formula (D) that can be an aldimine or a ketimine.

According to a particular embodiment, the present invention relates to a method of preparation of tertiary amines of formula (E)

wherein R₁ represents an aryl, allyl, C₁ to C₁₀ alkyl or C₃ to C₁₀ cycloalkyl, R₂ represents a hydrogen, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.

According to another particular embodiment, the present invention relates to a method of preparation of tertiary amines of formula (E)

wherein R₁ and R₂ represent an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.

According to a particular embodiment, the present invention relates to a method of preparation of tertiary amines of formula (E)

wherein R₁ is an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₂ represents a hydrogen, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl or a C₃ to C₁₀ cycloalkyl; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.

According to a particular embodiment, the present invention relates to a method of preparation of tertiary amines of formula (E)

wherein R₁ and R₂ represent an aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, alkyl C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E)

wherein the tertiary amine of formula (E) carries three different substituents and wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ is C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the alcohol of formula (C) is chosen from ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, amyl alcohol, isopentanol, neopentyl alcohol, methyl-n-propylcarbinol, hexan-1-ol, heptan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol, ethylene glycol.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is catalyzed by an iron(0) complex.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is catalyzed, in particular by an iron(0) complex, chosen from the following formulas:

wherein Ts=tosyl

TMS=trimethylsilyl

TBDMS=tert-butyldimethylsilyl

TIPS=triisopropylsilyl

and preferably being of the following formula (B):

in which TBDMS=tert-butyldimethylsilyl

Ts=tosyl

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is catalyzed by the complex of formula (B).

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is catalyzed either by the complex of formula (B) formed prior to the preparation of tertiary amines, or the catalyst formed in situ during said preparation of tertiary amines by adding trimethylamine oxide to the complex of formula (A).

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is performed at a temperature of 80° C. to 130° C., and preferably at 110° C.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is performed in an organic solvent.

Said organic solvent can be:

-   -   a single solvent chosen from ethanol, ethylene glycol,         tetrahydrofuran, dichloroethane, toluene, methoxycyclopentane,         diethyl ether.     -   a mixture of solvents chosen from the above mentioned solvents         or     -   the alcohol of formula (C) used as a solvent and as a reactant         in the method of preparation of tertiary amines of formula (E).

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is performed in ethanol or ethylene glycol used as solvent and as reactant, or in a mixture of solvents composed in particular of THF and of ethanol or of ethylene glycol, ethanol or ethylene glycol being used as a solvent and reagent.

The use of ethanol, and more generally the alcohol of formula (C), both as a solvent and as a reactant in this method of preparation of tertiary amines of formula (E) makes it possible to carry out the reaction in the presence of a large excess of one of the two reactants, which promotes the reaction. The second interest is to avoid the use of another solvent, which makes the reaction more simple to implement and more economic.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the primary alcohol of formula (C), in particular ethanol or ethylene glycol is also used as solvent for the step of alkylation, in particular in a number of equivalents higher than 10 equivalents, and preferably 85 equivalents.

The use of a solvent composed of primary alcohol of formula (C) in admixture with another solvent in the method of preparation of tertiary amines of formula (E) can be carried out according to the solvent/primary alcohol (C) proportions ranging from 1/1 to 13/1.

When the primary alcohol of formula (C) is used both as solvent and as reactant in the method of preparation of tertiary amines of formula (E), at least 10 equivalents of primary alcohol of formula (C) are used and preferably 85 equivalents.

When an organic solvent other than the primary alcohol of formula (C) is used, 3 equivalents of primary alcohol of formula (C) are used as reagent.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the concentration of imine of formula (D) is comprised from 0.05 M to 0.4 M, in particular of 0.1 M, 0.2 M, 0.3 M, 0.4 M, and is preferably 0.2 M.

According to another embodiment, the invention relates to a method of preparation of tertiary amines formula (E), wherein the amount of catalyst is comprised from 1 to 20 mol %, in particular from 1 to 5 mol %, 5 to 10 mol %, 10 to 15 mol %, 15 to 20 mol %, and is preferably 5 mol %, relative to the molar amount of imine

According to a preferred embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the step of alkylation is performed at a temperature of 110° C. for 24 hours in ethanol with a concentration of imine of formula (D) of 0.2 M and a quantity of catalyst of 5 mol %.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), wherein the imine of formula (D) is either formed prior to the preparation of the tertiary amines, or is formed in situ during said preparation of tertiary amines by a method comprising contacting an aldehyde or ketone of formula (F)

wherein R₁, R₂ represents a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, and an amine of formula (G)

R₃—NH₂  (G)

wherein R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative or a C₃ to C₁₀ formate.

According to the above embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a step of preparing tertiary amines of formula (E) comprising a step of alkylation of an alcohol of formula (C) to an imine of formula (D) wherein the imine of formula (D) is either formed prior to the preparation of tertiary amines, or formed in situ during said preparation of tertiary amines by a method comprising contacting an aldehyde or a ketone of formula (F), and an amine of formula (G), the step of alkylation being performed in the presence of a catalyst of formula (B) either preformed or formed in situ in a first step prior to the step of alkylation.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a step of preparing tertiary amines of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, in the presence of a catalyst of formula (B)

to obtain the compound of formula (E) as defined above, or comprising a first step of preparing of the catalyst comprising a step of adding trimethylamine oxide on the complex of formula (A)

and a second step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl or a C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the presence of a catalyst of formula (B) prepared during the preceding step and as defined above, to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above, or comprising a first step of preparing imines of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or cycloalkyl C₃ to C₁₀, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, comprising a step of contacting with an aldehyde or a ketone of formula (F)

wherein R₁ and R₂ are as defined above, and an amine of formula (G)

R₃—NH₂  (G)

wherein R₃ is as defined above, to obtain the imine of formula (D) as defined above; and a second step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D) prepared in the preceding step and as defined above, in the presence of a catalyst of formula (B)

to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above, or comprising a prior step of preparing of imines of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, comprising a step of contacting an aldehyde or ketone of formula (F)

wherein R₁ and R₂ are as defined above, and an amine of formula (G)

R₃—NH₂  (G)

wherein R₃ is as defined above, to obtain the imine of formula (D) as defined above; a prior step of preparing the catalyst comprising a step of adding trimethylamine oxide to the complex of formula (A):

said two prior steps may occur in any order, and a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D) prepared in the previous step

wherein R₁, R₂ and R₃ are as defined above, in the presence of catalyst of formula (B) prepared in the preceding step and as above, to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a step of preparing tertiary amines of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl or C₃ to C₁₀ cycloalkyl; comprising a step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, in the presence of a catalyst of formula (B)

to obtain the compound of formula (E) as defined above.

According to a preferred embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a step of alkylation of a primary alcohol of formula (C) to an imine of formula (D) in the presence of a catalyst of formula (B) formed prior to the preparation of the tertiary amines.

According to a preferred embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a step of alkylation of a primary alcohol of formula (C) to an imine of formula (D) in the presence of a catalyst of formula (B), the imine of formula (D) and the catalyst of formula (B) being formed prior to the preparation of the tertiary amines.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a first step of preparing of the catalyst,

comprising a step of addition of trimethyl amine oxide to the complex of formula (A)

and a second step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the presence of a catalyst of formula (B) prepared in the preceding step and as defined above, to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a first step of preparing imines of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, comprising a step of contacting with an aldehyde or a ketone of formula (F)

wherein R₁ and R₂ are as defined above, and an amine of formula (G)

R₃—NH₂  (G)

wherein R₃ is as defined above, to obtain the imine of formula (D) as defined above; and a second step of alkylation of an alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D) prepared in the preceding step and as defined above, in the presence of a catalyst of formula (B)

to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above.

According to another embodiment, the invention relates to a method of preparation of tertiary amines of formula (E), comprising a prior step of preparing of imines of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative or a C₃ to C₁₀ formate, comprising a step of contacting an aldehyde or ketone of formula (F)

wherein R₁ and R₂ are as defined above, and an amine of formula (G)

R₃—NH₂  (G)

wherein R₃ is as defined above, to obtain the imine of formula of formula (D) as defined above; a prior step of preparing of the catalyst, comprising a step of adding trimethylamine oxide to the complex of formula (A):

said two prior steps may occur in any order, and a step of alkylation of a primary or secondary alcohol of formula (C)

R₄OH  (C)

wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl on an imine of formula (D) prepared in the previous step

wherein R₁, R₂ and R₃ are as defined above, in the presence of catalyst of formula (B) prepared in the preceding step and as defined above, to obtain the compound of formula (E)

wherein R₁, R₂, R₃, and R₄ are as defined above.

According to a preferred embodiment of the invention, the imine of formula (D) is chosen from:

The present invention also relates to novel tertiary amines having one of the following formulas:

The present invention also concerns new tertiary amines of one of the following formula:

Amines having long carbon chains, especially tertiary, are of great industrial interest. They are used in the synthesis of chemical compounds, as surfactants (corrosion inhibitors, detergents, flotation agents, emollients, softeners, antistatics, germicides, insecticides, dispersant, anti-caking agents, emulsifiers, lubricants, water treatment agents, food additives, cosmetics, etc.).

Amines having long carbon chains, especially allylic, are fundamental elements of organic chemistry and their synthesis is an important industrial and synthetic objective. The allyl amine moiety can be found in natural products, but often, allylamine is converted into a range of products by functionalization, reduction or oxidation of the insaturation. Thus, amines can be used as raw materials for the synthesis of many compounds such as amino acids, alkaloids and carbohydrate derivatives.

Tertiary amines are important intermediates for the preparation of asymmetric quaternary ammonium salts of formula

to access active agents whether for pharmaceutical or cosmetic use. They are used as surfactants, biocides for water treatment, flotation agent, petrol based detergent, corrosion inhibitors, processing rubber additives or emulsifiers for herbicides.

EXAMPLES Example 1 Study of the Catalyst

TABLE 1 Tests with different iron catalysts

Ratio GC (starting/ Catalyst. Additive reduction/alkylation) Yield [%] A Me₃NO 0/0/100 97 B — 0/0/100 99

Example 2 Study of the Solvent

TABLE 2 Tests with different solvents

Temperature Ratio GC(starting/reduction/ Solvent [° C.] alkylation/dialkylation) DCE/EtOH  80 18/72/10/0 (svt/3 eq) THF/EtOH  80 27/65/8/0 (svt/3 eq) THF/EtOH (1/1)  80 15/1/79/5 THF/EtOH (1/1) 110 23/5/72/0 CPME/EtOH (1/2) 110 73/18/9/0

Example 3: Study of the Alcohol

TABLE 3 Study of several alcohols as alkylating agents

Ratio GC(starting/reduction/ Yield Catalyst Alcool alkylation/dialkylation) [%] B ethylene glycol 0/0/100/0 18 B ethanol 0/0/100/0 99

Example 4: Aromatic Imines

TABLE 4 Exemplification with various aromatic aldehydes, substituted in the para position

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

A/Me₃NO B 16/23/48/13 5/20/74/1 28 68

A/Me₃NO B 0/0/100/0 0/0/88/12 88 55

A/Me₃NO B 0/0/100/0 0/0/100/0 97 99

A/Me₃NO B B à 130° C. 35/25/40/0 45/37/18/0 6/39/55/0 33 15 50

A/Me₃NO B 3/50/35/12 8/13/75/4 26 68

A/Me₃NO B 48/33/19/0 0/0/86/14 12 74

A/Me₃NO B 34/19/43/4 0/0/84/16 54 85

A/Me₃NO B — 0/29/41/30 — 38

B 36/39/25/0 20

TABLE 5 Exemplification with various aromatic aldehydes

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

A/Me₃NO B — 19/3/78/0 — 70

A/Me₃NO B — — 70 72

A/Me₃NO B 0/0/83/17 0/0/72/28 49 55

A/Me₃NO B 0/0/92/8 0/0/90/10 78 70

A/Me₃NO B — 5/0/90/5 — 78

A/Me₃NO B — 0/31/29/40 — 21

B 0/0/15/85 10

Example 5: Allylated Imines

TABLE 6 Exemplification with various conjugated aldehydes

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

A/Me₃NO B — — 67

A/Me₃NO B — 48 30

Example 6: Alkylated Imines

TABLE 7 Exemplification with various aliphatic aldehydes

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

A/Me₃NO B — 0/0/78/22 52 54

A/Me₃NO B — 0/40/17/43 — 14

Example 7: Aromatic Imines

TABLE 8 Exemplification with various aromatic amines

Ratio GC (starting/reduction/ Alkylation Product akylation/dialkylation) yield [%]

0/58/42/0 30

0/10/90/0 88

45/37/18/0 12 0/34/36/30 18

TABLE 9 Exemplification with various aliphatic amines

Ratio GC (starting/reduction/ Alkylation Product akylation/dialkylation) yield [%]

0/0/100/0 85

0/0/100/0 85

0/0/67/33 51

0/0/100/0 75

0/0/100/0 47

39/9/52/0 18

Example 8: Allylated Imines

TABLE 10 Exemplification with various substituted aromatic amines

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

A/Me₃NO B — 0/0/100/0 — 57

A/Me₃NO B — 0/0/100/0 — 85

A/Me₃NO B — Incomplete conversion — 38

A/Me₃NO B — 0/0/100/0 — 88

A/Me₃NO B — 0/0/100/0 — 72

A/Me₃NO B — 0/0/100/0 — 55

A/Me₃NO B — 0/8/92/0 — 76

B 0/0/100/0 15

TABLE 11 Exemplification with various allylic or aliphatic amines

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

B 0/0/100/0 22

Example 9 Other Imines

TABLE 12 Exemplification with various imines

Ratio GC (starting/reduction/ Alkylation Product Catalyst akylation/dialkylation) yield [%]

A B — 23/42/35/0 — 30

A B — 0/4/96/0 — 78

A B — 0/47/35/18 — 35

A B — 0/0/90/10 ou 0/0/83/17 — 71

A B — 0/27/73/0 (or starting 27) — 53

A B — 0/0/100/0 — 29

B 0/0/87/13 80 Cond A: [Fe] (5 mol %), Me₃NO (5 mol %), EtOH 110° C. Cond B: [Fe][MeCN] (5 mol %), EtOH 110° C.

Example 10: Intermolecular Version

TABLE 13 Optimization of the intermolecular version on the model substrates

Ratio GC (starting/ Catalyst Additive Temperature [° C.] reduction/akylation/dialkylation) Yield [%] B — 110 0/0/68/32 65

TABLE 4 Exemplification of the intermolecular version of the reaction

Ratio GC (starting/reduction/ Alkylation Product akylation/dialkylation) yield [%]

18/0/34/48/ ou 0/18/34/48 10

48/0/34/19 26

0/0/54/46 35

51/0/29/20 19

Alkylation Reactions of Imines (Conditions A)

In the glove box, catalyst A (0.05 eq.), trimethylamine oxide (0.05 eq.), previously distilled and degassed ethanol (0.05 M) were introduced into a tube equipped with a magnetic stirrer. The reaction mixture was stirred at room temperature for 30 minutes. The substrate (50 mg, 1 eq.) was then added, the tube was sealed with a Teflon plug and removed from the glovebox. Thereafter, the reaction tube is immersed in a bath preheated to 110° C. and stirred for 24 hours. After returning to ambient temperature, the reaction is stopped by adding methanol (1 ml) and sodium hydroxide (1 ml, 1 M). The organic phases are extracted with 3×5 ml of diethyl ether, washed with a saturated solution of sodium chloride (5 ml), then dried over magnesium sulfate and concentrated under reduced pressure. The crude product is purified by chromatography on silica gel column (12 g SiO₂ already treated with 5% triethylamine, cyclohexane/ethyl acetate, 95/5) to obtain the desired alkyl amine.

Alkylation Reactions of Imines (Conditions B)

In a catalyst tube (10 ml), equipped with a magnetic stirrer, the substrate (50 mg, 1 eq.), the catalyst B (0.05 eq.) and ethanol previously distilled and degassed (0.05 M) are introduced. The tube was placed under argon and then sealed with a Teflon stopper. Thereafter, the reaction tube is immersed in a bath preheated to 110° C. and stirred for 24 hours. After returning to ambient temperature, the reaction is stopped by adding methanol (1 ml) and sodium hydroxide (1 ml, 1 M). The organic phases were extracted with 3×5 ml of diethyl ether, washed with a saturated solution of sodium chloride (5 ml), then dried over magnesium sulfate and concentrated under reduced pressure. The crude product is purified by chromatography on silica gel column (12 g SiO₂ already treated with 5% triethylamine, cyclohexane/ethyl acetate, 95/5) to obtain the desired alkyl amine. 

1-11. (canceled)
 12. Method of preparation of tertiary amines comprising the use of an alcohol, with the exception of methanol, and of an imine.
 13. The method according to claim 12, wherein the alcohol is a primary or secondary alcohol.
 14. The method according to claim 12, wherein the tertiary amine carries three different substituents.
 15. The method according to claim 12, wherein the alcohol is ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, and wherein the imine is an imine of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, wherein the tertiary amines are of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above.
 16. The method according to claim 12, wherein the preparation of tertiary amines is performed in the presence of a catalyst.
 17. The method according to claim 12, wherein the preparation of tertiary amines is performed in the presence of a catalyst comprising an iron(0) complex chosen from the following formulas:

in which Ts=tosyl

TMS=trimethylsilyl

TBDMS=tert-butyldimethylsilyl

TIPS=triisopropylsilyl


18. The method according to claim 12, wherein the preparation of tertiary amines is performed in the presence of a catalyst, said catalyst being of the following formula (B):

in which TBDMS=tert-butyldimethylsilyl

Ts=tosyl


19. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.
 20. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said tertiary amine of formula (E) carrying three different substituents, different from a hydrogen atom, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above.
 21. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the step of alkylation is catalyzed.
 22. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the step of alkylation is catalyzed by an iron(0) complex, chosen from the following formulas:

wherein Ts=tosyl

TMS=trimethylsilyl

TBDMS=tert-butyldimethylsilyl

TIPS=triisopropylsilyl

or by an iron(0) complex of the following formula (B):

in which TBDMS=tert-butyldimethylsilyl

Ts=tosyl


23. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the step of alkylation is catalyzed either by the complex of formula (B) formed prior to the preparation of tertiary amines,

in which TBDMS=tert-butyldimethylsilyl

Ts=tosyl

or by the catalyst formed in situ during said preparation of tertiary amines by adding trimethylamine oxide to the complex of formula (A).


24. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the step of alkylation is performed in an organic solvent, or in ethanol, or ethylene glycol, or in a mixture of solvents, or in a mixture of solvents composed of THF and of ethanol or of ethylene glycol.
 25. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the primary alcohol of formula (C), is also used as solvent for the step of alkylation.
 26. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the primary alcohol of formula (C), is also used as solvent for the step of alkylation, in a number of equivalents higher than 10 equivalents, and preferably 85 equivalents.
 27. The method according to claim 12, wherein the tertiary amines are of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, said method comprising a step of alkylation of ethanol or an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, to obtain the compound of formula (E) as defined above, wherein the imine of formula (D) is either formed prior to the preparation of the tertiary amines, or is formed in situ during said preparation of tertiary amines by a method comprising contacting an aldehyde or ketone of formula (F)

wherein R₁, R₂ represents a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, and an amine of formula (G) R₃—NH₂  (G) wherein R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative or a C₃ to C₁₀ formate.
 28. The method according to claim 12, comprising a step of preparing tertiary amines of formula (E)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl; comprising a step of alkylation of an alcohol of formula (C) R₄OH  (C) wherein R₄ is as defined above, on an imine of formula (D)

wherein R₁, R₂ and R₃ are as defined above, in the presence of a catalyst of formula (B)

to obtain the compound of formula (E) as defined above, or comprising a first step of preparing of the catalyst comprising a step of adding trimethylamine oxide on the complex of formula (A)

and a second step of alkylation of an alcohol of formula (C) R₄OH  (C) wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl or a C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, in the presence of a catalyst of formula (B) prepared during the preceding step and as defined above, to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above, or comprising a first step of preparing imines of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or cycloalkyl C₃ to C₁₀, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, comprising a step of contacting with an aldehyde or a ketone of formula (F)

wherein R₁ and R₂ are as defined above, and an amine of formula (G) R₃—NH₂  (G) wherein R₃ is as defined above, to obtain the imine of formula (D) as defined above; and a second step of alkylation of an alcohol of formula (C) R₄OH  (C) wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D) prepared in the preceding step and as defined above, in the presence of a catalyst of formula (B)

to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above, or comprising a prior step of preparing of imines of formula (D)

wherein R₁ and R₂ represent a hydrogen, aryl, allyl, C₁ to C₁₀ alkyl, or C₃ to C₁₀ cycloalkyl, R₃ represents an aryl, allyl, C₁ to C₁₀ alkyl, C₃ to C₁₀ cycloalkyl, a C₁ to C₁₀ carbonyl derivative, or a C₃ to C₁₀ formate, comprising a step of contacting an aldehyde or ketone of formula (F)

wherein R₁ and R₂ are as defined above, and an amine of formula (G) R₃—NH₂  (G) wherein R₃ is as defined above, to obtain the imine of formula (D) as defined above; a prior step of preparing the catalyst comprising a step of adding trimethylamine oxide to the complex of formula (A):

said two prior steps may occur in any order, and a step of alkylation of an alcohol of formula (C) R₄OH  (C) wherein R₄ represents a C₂ to C₁₀ alkyl, or a C₃ to C₁₀ cycloalkyl, on an imine of formula (D) prepared in the previous step

wherein R₁, R₂ and R₃ are as defined above, in the presence of catalyst of formula (B) prepared in the preceding step and as above, to obtain the compound of formula (E)

wherein R₁, R₂, R₃ and R₄ are as defined above.
 29. Tertiary amines having one of the following formulas: 